Dental matrix holder



June 16, 1936. w HARPER DENTAL MATRIX HOLDER Filed Oct. 26, 1954 0 4, 1MM rm m/ m w I Z Patented June 16, 1936 UNITED STATES PATENT OFFICE 9Claims.

This invention relatesto new and useful improvements in dental matrixholders.

Specifically this invention is directed to improvements over theinventions disclosed and claimed in my Patent No. 1,908,145 granted May9-, 1933, directed to Dental matrix holder jaw.

The results obtained by-using the improved jaw therein described whilefar superior to the results obtained before were lacking to some extentfor under certain circumstances of peculiar cavity formation the matrixband did not completely conform to the anatomical form of the tooth andthe resultant rough or overhanging edge of the filling necessitatedtedious grinding and polishing.

My present invention is provided to overcome this difficulty and topresent a completely improved matrix holder for dental work.

The principal object of the invention is to provide a supplemental wedgemember associated with the flexible jaws adapted to be used optionally.

Another object is to provide a new means for securing the jaws to thearms of the holder so as to obtain the maximum leverage at the desiredpoint.

Another object is to provide a novel clamping bar for the arms of theholder which is reversible so as to position the screw head at eitherside of the holder and. formed so as to permit the holder to bepositioned at the lowest possible angle when inoperation. 1

Still another object is to provide the arms of the holder with slots topermit easy removal by means of rubber dam forceps.

Numerous other objects and advantages will be apparent from thefollowingdetailed description.

In the accompanying drawing:

Fig. 1 is a plan view of my improved dental matrix holder.

Fig. 2 is a side elevation of the structure of Fig. 1.

Fig. 3 is a sectional View taken along line 3-3 of Fig. 1.

Fig. 4 is a sectional view taken along line 4-4 of Fig. 2.

Fig. 5 is a sectional view taken along line 55 of Fig. 2.

Fig. 6 is a perspective view of the supplemental wedge member.

Fig. 7 is a perspective view of one of the jaws.

Fig. 8 is a perspective view of one of the jaw and wedge member holders.

Referring more particularly to the drawing wherein like andcorresponding parts are designated by similar reference charactersthroughout, I indicates the arms. of the holder pivotally joinedtogether by pin. 2 and held in closed position by spring 3 secured toeach arm near the pivot point. Notches' I a are provided on the insideedges of the arms I for the purpose hereinafter described. The clampingbar 4. is interiorly threaded at one end. 5 to receive the. screw 6having a knurled. head I. The is longitudinally slotted'as at 8 soas toreceive the arms I of the holder and a portion. of one side of the baris cut away as at 9 to permit the removal and reversal of the bar asdesired.

The: outer ends of the arms. l are looped as at It to form substantiallycircular apertures ll.

Through these apertures are positioned the threaded shanks I2 of the jawand wedge member holders [3 which shanks extend at right angles to andfrom the ends of the holders proper which are secured in this. positionby means of spring washers l4 and knurled nuts ['5 as clearly shown inFig. 4.. The holders I 3 are provided with slots Hi and circularapertures H which extend through the shanks I2. The flexible jaws l8 areprovided in their backs with circular apertures I9 positioned below thecenters for the reason hereinafter explained. The wedge member 20:comprises'a tubular shank 2f slotted as at 22 and a wedge shaped end 23.The slot 22 permits the wedge to be sprung apart slightly so as topresent a yieldable frictional fit as hereinafter described.

In the assembly the back of a jaw i8 is positioned within the slot [6'of the holder l3 with the aperture [9 aligned with the aperture ll ofthe holder. The wedge member 20 is then forced through these aperturesuntil the wedge shaped end 23' is within the jaw I8 and the other endextends from the other side of the holder as at 24, Fig. 5. As explainedthe wedge is yieldably held in this position due to the slot 22. Thiswedge member 20 holds the jaw I8 in position so that in operation theforce moving the jaws together will be directed against the lowerportion of the jaws. The holder I3 with this assembly is then secured toone of the arms I as hereinbefore described.

In operation the matrix band is positioned between two teeth adjacentthe approximal cavity, the jaws of the matrix holder are then alsopositioned between the teeth with the band between them and the cavityand the spring 3 holds this initial position. The clamping bar 4 havingbeen placed on the arms I with the head 1 to the desired side so as notto interfere and the cut away portion 9 down so as to permit the lowestpositioning of the holder, the screw 6 is then tightened so as to causethe arms to move toward each other. This action causes the jaws toapproach one another, the flexible arms thereof forming the matrix bandto the tooth having the cavity. If upon examination it is thendetermined that a further forming of the band is necessary to insureperfecting the anatomical shape of the tooth, the extending shanks 2| ofthe wedge members 20 as shown at 24 are then pressed toward the opposingone, thus forcing the wedges between the jaws to spread them thusforcing the lower part of the matrix against the tooth to supplement theaction of the flexible jaws in forming the matrix band.

To effect removal of the holder after filling the tooth the screw 6 ofthe clamping bar is loosened to permit the bar to be moved toward thepoint of pivot or to be removed and the arms are forced apart by rubberdam forceps the ends of which are positioned within the notches la.

It can readily be seen that by use of the bar clamp herein described theknurled head of the screw can be positioned at one side or the other sothat it will be out of the way at all times.

I claim:

1. A dental matrix holder comprising a pair of arms pivotally joinedtogether to present a pair of free ends, resilient jaws secured to thefree ends of the arms, and a supplemental wedge member movablypositioned within each of said jaws.

2. A dental matrix holder comprising a pair of arms pivotally joinedtogether to present a pair of free ends, resilient jaws secured to thefree ends of the arms, and a supplemental wedge member movablypositioned within each of said jaws adapted to be independently movedinwardly from said arms comprising a cylindrical shank extending throughsaid jaw members.

3. A dental matrix holder comprising a pair of arms pivotally joinedtogether to present a pair of free ends, holding members secured to thefree ends of the arms, jaw members secured to the holding members andsupplemental wedge members movably positioned within said jaw memberscomprising wedge portions and cylindrical shanks extending through saidholding members.

4. A dental matrix holder comprising a pair of arms pivotally joinedtogether to present a pair of free ends, loops formed by the free endsof said arms, holding members secured to said ends through said loops,wedge shaped resilient jaw members secured to said holding members, andsupplemental wedge members each comprising a wedge shaped head and acylindrical shank, the wedge shaped head portion positioned within a.jaw member with the shank portion extending through said jaw member andholding member.

5. A dental matrix holder comprising a pair of arms pivotally joinedtogether to present a pair of free ends, loops formed by the free endsof said arms, holding members provided with vertically extending slotssecured to said ends through said loops, resilient jaw members eachcomprising a back portion, a, pair of shoulders, a pair of wallsconverging from said shoulders, the back portions fitting within theslots of the holding members and a supplemental wedge member movablypositioned within each jaw member between said converging walls andextending through the back of said jaw and said holding member.

6. A dental matrix holder comprising a pair of arms pivotally joinedtogether to present a pair of free ends, loops formed by the free endsof said arms, holding members provided with vertically extending slotssecured to said ends through said loops, jaw members each comprising avertically extending back portion, a pair of shoulders, a pair of wallsconverging from said shoulders, the back portions fitting within theslots of the holding members to position said jaw member, a slottedsupplemental wedge member movably positioned within each jaw memberbetween said converging walls and extending through the back of said jawand said holding member to present an end portion adapted to be pressedto move said supplemental wedge member between the walls of said jaw.

'7. A dental matrix holder comprising a. pair of arms pivotally joinedtogether at one pair of ends to present a pair of free ends, holdingmeans each comprising a vertically slotted head and a hollow shanksecured to the free ends of said arms, jaw members each comprising aback portion formed with an aperture adjacent the lower part of the jaw,a pair of shoulders, a pair of walls converging from said shoulders,said back portions fitting within the slots of the holding members, theapertures aligned with the hollow portions of the shanks andsupplemental wedge members movably positioned within each jaw memberbetween said converging walls and extending through the said aperturesand hollow shanks and yieldably held there so as to be optionally movedinwardly to supplement the action of the said jaw members.

8. A dental matrix holder comprising a pair of arms pivotally joinedtogether at one pair of ends, the other ends being free, notches on theinner edges of said arms to facilitate removal, spring jaws on said freeends and supplemental wedge members movably mounted within said springaws.

9. A dental matrix holder comprising a pair of arms pivotally joinedtogether at one pair of ends, the other ends being free, spring jawsmounted on said free ends and supplemental wedge members movably mountedwithin said spring jaws below the horizontal centers thereof.

WILLIAM E. HARPER.

